That, which or who? A handy guide to relative pronouns

That or which? Who or whom? Whose or who’s? For such little words, relative pronouns can cause an awful lot of confusion. Here are some tips to help you sort them out

Photograph by Wil Stewart

Relative pronouns are words that join relative clauses to the rest of a sentence, and confusion often arises as to which one to use or whether you need one at all: “The beach that we visited”, “The beach which we visited” or “The beach we visited”? In fact relative pronouns follow fairly simple rules and in some cases there is more than one option. And yet – at the risk of losing everyone in the very first paragraph I’m going to kick off with some juicy grammatical definitions to save things getting too long-winded later on. Plus, I love this technical nitty gritty kind of stuff – but feel free to skip to the main part* if you don’t find it quite so fascinating…**

(**But how could you not?)

Clause A group of words including a subject and a verb that form part of a sentence

Head noun The noun in a phrase that controls the verb and which is essential to the meaning of the clause

Noun phrase A phrase that consists of a head noun, a determiner (a, the, many), the premodification (ie, something that comes before the noun and modifies it – usually an adjective) and the postmodification (ie, anything that comes after the head noun and modifies it)

Verb phrase One or more verbs in a phrase, eg, I ran, I didn’t run, I couldn’t have been running; they comprise a main verb and up to four auxiliary verbs that all come before the main verb

Finite verb phrase A verb phrase in which the main verb changes depending on number or tense, eg, he jumps/they jump; he jumps/he jumped – as opposed to a…

Non-finite verb phrase A verb phrase in which the main verb does not change whatever the person, number or tense, eg, I’m going/he’s going/we’re going/I was going/I am going; he laughed/we laughed; they will go/they did go. The verb often ends in “-ing”, -“ed” or “en”, or takes the infinitive form (the to form, ie, to go, to walk, to eat)

Finite clause A clause containing finite verb phrases

So from all of that, THIS should now make sense:

Relative clause A finite clause that postmodifies a noun phrase

As should THIS:

Relative pronoun A pronoun that introduces a relative clause

But! I am not done yet. There are two types of relative clause:

Defining (or restrictive) relative clause A relative clause that is essential to define exactly what or whom the head noun refers to. For instance, “My friend who lives in Paris is coming to stay.” Which friend is coming to stay? The one “who lives in Paris” – without that clause we could be referring to any friend.

Non-defining (or non-restrictive) relative clause A relative clause that provides additional, non-essential information that could be removed from the sentence without affecting the noun’s identity. So, “My friend Juliette, who lives in Paris, is coming to stay.” Here, “who lives in Paris” is not essential to identifying the friend because we already know that she is Juliette. Same words but now a non-defining relative clause.

Aw, come on, you love this stuff, right?

*THE MAIN PART: So, a relative pronoun is a pronoun that introduces a relative clause and refers back to the head noun of the sentence. Here’s how to choose correctly…

That Use that when the noun is a thing, to introduce a defining relative clause: “I used to catch the bus that went down Maple Avenue to get to work.” (Which bus? Specifically the bus that went down Maple Avenue.)

Which Use which when the noun is a thing, to introduce a non-defining relative clause: “I recently found my grandmother’s necklace, which she used to wear all the time, at the back of a drawer.” (The necklace is already identified as my grandmother’s – the fact that she wore it all the time is additional information so we use which to introduce it).

Who Use who when the noun is a person or – if you like – a pet, for both defining and non-defining relative clauses: “The man who stole my hat was wearing a blue coat”; “The lady with the pink hair, who used to live opposite me, has gone on holiday.” You could also use that and it wouldn’t be wrong, but I think who sounds more natural.

Whom Yes it sounds formal. No you don’t have to use it. But should you wish to (and I still think it has a certain elegance) then use whom when the noun you are modifying is the object of the verb, ie, something is being done to it. In other words you could replace the noun with him or her, not he or she. As in, “The singer, whom you invited to the party, will be here at seven.” (You invited her to the party…) In conversation most people would use either who or would not use a relative pronoun at all (“The singer you invited to the party…”) and that’s fine. But it’s still useful to know how to use whom in case you, erm, ever need to write to the Queen, for example.

Whose Whose essentially means “of whom” and can be used with both defining and non-defining clauses: “The new employee whose desk is by the window needs a better chair”; “Her former maths teacher, whose classes she never missed, paid her a visit.”

Who’s The actual relative pronoun here is just the who bit – who’s is a contraction of who is or who has. So: “My best friend, who’s just moved house, needs a new kettle.” It’s often used incorrectly as a possessive pronoun so look out for that (ie, DON’T write, “The man who’s house she bought”; see also its/it’s).

The zero relative This is a cool name for, erm, nothing. As with “whom”, above, the relative pronoun can be missed out when it does not refer to the subject of the sentence: “The apple tree I planted five years ago has not produced any fruit.” The tree is the object, because it was planted by me (the subject), so the meaning is clear without saying, “The apple tree that I planted…” However, if we make the apple tree the subject, the pronoun remains: “The apple tree that was planted five years ago has not produced any fruit.”

By the way, note that non-defining relative clauses are always separated from the rest of the sentence by punctuation – usually commas or dashes: “Her three daughters – who together were known as the Merryweather girls – were all talented dancers.” Punctuation makes it clear that even if that section of the sentence were removed then the rest of the sentence would still make sense.